> Reiserfs is a completely new file system initially designed by Hans Reiser
> and his team that has journalling capabilities, uses balanced b-trees for directory
> searches (unlike ext2 which uses linear dsearch) and block allocation,
> features highly optimized file access. Go to http://www.devlinux.com/namesys
> for more info
>
> ext3 adds journalling to the ext2
>
> XFS(tm) is an SGI project (open source) to port their high performance, fool
> proof, journalling, 64-bit file system to Linux. For details see
> http://oss.sgi.com/projects/xfs/
And then there's IBM's JFS:
http://oss.software.ibm.com/developerworks/opensource/jfs/